It was supposed to be the vacation of a lifetime. It turned into a nightmare no traveler could anticipate.

A couple’s first vacation in three years ended in tragedy when a Poughkeepsie doctor was gunned down in the parking lot of the Newark Airport hotel he and his wife had just checked into.

Eminent oncologist Dr. Jeffrey Perchick, 55, and his wife of 31 years, Jo Anne, decided to drive from their home to the Wyndham Hotel on the perimeter of the airport last Friday night, rather than leave very early Saturday to negotiate the long security lines.

They had planned to catch a flight to Los Cabos, Mexico.

But as Jo Anne stood in the hotel lobby with their luggage, waiting for her husband to park their car, the unthinkable happened.

Perchick was shot in the head and killed by a robber who stole his wallet and ID.

“I lost my soulmate, the love of my life. How does one recover from that?” Perchick’s devastated widow told The Post yesterday.

“We planned a relaxed trip down to the airport. We didn’t want to have to get up at 5 in the morning and rush.

“We pulled up at the front of the hotel, took the baggage inside and checked in, then Jeffrey went back out to park the car.

“He never returned.”

Police believe the doctor was watched while he checked into the Route 1 hotel and then followed when he walked out to drive his black 1994 Chrysler into the lot.

A witness told cops she saw a man wearing a checkered jacket going through the pockets of a man, presumably Perchick, lying on the ground in the lot.

“The victim was stalked and selected by the killer, accosted, then shot and robbed,” said Union County Assistant Prosecutor Robert O’Leary.

Detectives believe the killer entered the lot by getting through a chain-link fence at the rear of the hotel, which backs onto an area of low-rent motels and housing projects a few blocks from the Newark-Elizabeth border.

They also are reviewing video tapes from all hotels along Route 1.

Many of the hotels say their bookings have increased by 10 percent as travelers check in overnight because of early airport arrivals needed for security.

The victim’s three children, Rebecca 28, Brian 25, and Larry, who turns 19 today, said they are still trying to come to terms with the loss of their beloved father.

“All they wanted to do was get a few extra hours of sleep and beat the lines for the morning flight,” said Larry.

“It’s unimaginable that this has happened.”

Rebecca said her parents had only recently began making plans to travel, now that the children had grown up.

The couple had jokingly called themselves “empty nesters,” she said.

“It was their first vacation in three years,” she said.

“My father was so devoted to his patients, he found it very difficult to leave.”

Marie Rose Baker, Perchick’s nurse for 22 years, said the doctor loved his patients.

“The best legacy that we can give him is to continue his great work in the community,” she said.

Police released a sketch of the suspect and posted a $5,000 reward for information leading to his arrest.

Anyone with information should call (908) 654-TIPS. All calls will be kept confidential.